JPS639718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video system consisting of a combination of a video camera and a video recorder.

Video recording systems consisting of a combination of a video camera and a video recorder are now entering their prime.

By the way, among such video recording systems, for example, in the case of simple video recording systems that use a cassette-type video tape recorder, most of them perform recording by connecting a camera to the recorder, or by connecting the camera to the recorder. If you operate the power button on the recorder while connected, or if you further operate the recording button, all circuits on the camera will be powered by the recorder's built-in power supply or other external power supply. The recorder will now be set to recording standby, and if you operate the trigger button on the camera in this state, a recording start signal will be output from the camera to the recorder. The recorder starts operating, and the video output from the camera at this time is recorded on tape by the recorder.

In other words, the reason for adopting such a configuration is that a camera uses an image pickup tube as a photographing means, and in the case of an image pickup tube, as is well known, the comparison is made between the start of power supply to the heater circuit and the time when the steady state is reached. It requires a long start-up time (approximately 10 seconds), so in order to be able to record immediately at any time, it is necessary to set the recorder to recording standby mode and to supply power to all camera circuits in advance. It's time to start.

On the other hand, today, in photographic cameras, 8mm motion picture cameras, etc., automation of the focus adjustment of the photographic lens is being actively carried out as the last thing left behind in the automation of photographic operations. In this trend, automation of the focus adjustment of the imaging lens of video cameras is once again becoming popular. By the way, when a video camera used in the above-mentioned video recording system is equipped with an automatic focus adjustment device, the following problems arise. That is, an automatic focusing device is often equipped with some form of photoelectric means in its detection section, and therefore, from the beginning of its operation until the end of correctly focusing the imaging lens on the object. The time depends largely on the imaging conditions, especially on the object conditions; if the object conditions are not very good, it will take a relatively long time to finish focusing, and therefore such automatic When a focus adjustment device is installed on a video camera applied to a video recording system such as the one described above, even if the camera is aimed at an object and the trigger button is immediately operated to record, the intended object will not be detected. This is an inconvenient problem in that it takes a certain amount of time to complete the focusing of the imaging lens on the image, which tends to deteriorate the quality of the image, especially at the beginning of the scene.

The present invention has been made in view of the above-mentioned circumstances, and is a video system consisting of a combination of a video camera and a video recorder. The above-mentioned inconvenience that is a concern when using an adjustment device, that is, the inconvenience that the image at the beginning of the scene is likely to deteriorate, can be avoided, and the image is always good from the beginning of the scene. Its primary objective is to provide an improved video system that can record video images.

With this purpose in mind, the present invention provides a video camera that converts a subject image into an electrical signal and outputs it, and a video recorder that records the electrical signal outputted from the video camera on a recording medium. The video system includes an automatic focus adjustment device for automatically focusing the photographic lens on an object, and a device for setting the video recorder to a recording standby state in which the recording head and recording medium move relative to each other. 1 switch, a second switch operated by a trigger member, a signal indicating completion of focus adjustment of the photographing lens outputted from the automatic focus adjustment device, and an operation signal of the second switch. and a recorder trigger circuit that receives the video recorder, and when the video recorder is set to the recording standby state by the first switch in the first mode, the second switch manipulated, and
Starting recording by the video recorder on the condition that focus adjustment of the photographing lens is completed, and in the second mode, when the video recorder is set to the recording standby state by the first switch, The present invention is characterized in that recording by the video recorder is started in response to the operation of the second switch, regardless of the focus adjustment state of the photographic lens.

According to a preferred embodiment of the present invention described below, in the system configuration described above, the automatic focus adjustment device can be operated by operating the second switch. As the second switch, first and second trigger switches are provided which are manually operated sequentially from outside the camera.
The automatic focus adjustment device is operated alone or together with other camera circuits by operation of a second trigger switch, and a subsequent operation signal of a second trigger switch is applied to the recorder trigger circuit. Alternatively, the automatic focus adjustment device is activated by operating the second trigger switch, and the operation signal of the second trigger switch is applied to the recorder trigger circuit, and the operation signal of the second trigger switch is applied to the recorder trigger circuit. A configuration has been proposed in which other camera circuits can be activated by operating trigger switch 1, but in these configurations, the automatic focus adjustment device is always activated while the recorder is set to recording standby. It is further advantageous in that it can eliminate the inconvenience caused by being placed in the room, and in particular can reduce power loss.

In addition, when an image pickup tube is used as an imaging means, as mentioned above, it takes a relatively long time from the start of power supply until it reaches its steady state. Even if you start recording immediately after the power supply starts, proper recording will not actually begin until some time later, and the image, especially at the beginning of the scene, will deteriorate significantly. However, in view of these problems, according to still another preferred embodiment described below, in order to more advantageously solve such problems, the above-mentioned image pickup tube reaches a steady operating state. A detecting means is additionally provided for detecting whether or not the image pickup tube has reached a predetermined steady state, and the output of the recorder trigger signal is prohibited until the detecting means detects that the image pickup tube has reached a predetermined steady state. A more advantageous configuration of the camera described above has been proposed.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, an example of a video recording system comprising a combination of a video camera and a cassette-type video tape recorder according to the present invention will be explained with reference to FIG. 1. ·Tape recorder
The VTR is connected with a connection cable CC, and power is supplied from the recorder VTR side to the camera CA side from the power supply EE equipped on the recorder VTR side via the cable CC, and on the other hand, the video signal is supplied from the camera CA side. In addition, the recorder trigger signal obtained by the circuit configuration described later, that is, the recording trigger signal.
A start signal is given to the recorder VTR side.

Here, a video camera CA according to the present invention and a video tape recorder having a well-known configuration
An outline of the operation of the video recording system shown in FIG. 1, which is combined with a VTR, during recording is as follows. That is,
First, connect the camera CA and recorder VTR with a cable.
When connected via CC, or in a connected state, the recorder according to the first switch of the present invention
When you operate the power button PB on the VTR side, power is supplied from the power supply EE installed on the recorder VTR side to all the circuits in the camera CA, and for example, heating of the image pickup tube IT is started and the camera is activated. Meanwhile, the recorder
On the VTR side, the recording button RB
Loading of the video tape contained in the tape cassette TC into the signal recording system and setting of the signal recording system to its operating state, i.e., recording head cylinder drive motor, capstan drive This will operate the motors and supply power to various circuit systems (in addition, the tape cassette TC, recorder
If the tape is being loaded into the signal recording system when it is loaded into the VTR, only the operating state of the signal recording system is set. In addition, in this state, the recorder VTR
On the other hand, the tape running system is in an inactive state and the tape is not running (this state of preparation for recording is called the recording standby state of the recorder VTR). Also, in this case, the image pickup tube on the camera CA side
Once the IT heating is completed, the camera CA will start outputting video signals.
And this is radar VTR through cable CC
It comes to be attached to the above-mentioned signal recording device system on the side.
In this state, when the camera CA is aimed at the intended object, the imaging lens L is automatically focused on the intended object by the action of the automatic focus adjustment device AFU, and the trigger button TB is
When the trigger switch SWT related to the second switch of the present invention is turned on by the operation of
When the SWT is operated and the focusing of the imaging lens on the object is completed, a recorder trigger signal, that is, a recording start signal is output, and this is input to the recorder VTR side through the cable CC, As a result, the tape running system on the recorder VTR side is activated, that is, for example, the pinch roller pinches the tape and presses it against the capstan, and the drive of the tape take-up reel is started to move the tape. The vehicle starts running, and the video signal from the camera CA at this time is recorded on the tape by the recorder VTR as is well known.

Next, a more specific example of the configuration of the embodiment of the video system according to the present invention, the outline of which has been explained above, will be explained.

Referring to Figure 2, first, the camera
During CA, HC is a heater circuit for the image pickup tube IT, VR is a variable resistor for voltage adjustment, TCC is a well-known image pickup tube control circuit including a high voltage generation circuit and a deflection circuit, etc., and VPC is a circuit that receives image scanning signals from the image pickup tube IT. a well-known video processing circuit that outputs a standard video signal,
AEC is a known automatic aperture control circuit that outputs an aperture control signal for controlling the aperture D based on the luminance signal (Y signal) from the video processing circuit VPC, and AFC outputs a focus adjustment signal for the imaging lens L. This is an automatic focus adjustment circuit in the above-mentioned automatic focus adjustment device AFU that outputs the output.These are the automatic focus adjustment circuits in the above automatic focus adjustment device AFU that output power supply EE equipped on the recorder VTR side by turning on the power switch SWP operated by the power button PB on the recorder VTR side. It is connected to the power line PL inside the camera CA so that power is supplied from the cable CC through the cable CC. Note that the video signal output from the video process circuit VPC is connected to the video signal output line.
A signal recording system RS having a well-known configuration is attached to the recorder VTR side through the VL and cable CC. Further, AEM is an automatic aperture adjustment motor that drives the aperture D based on the output of the automatic aperture control circuit AEC, and AFM is the automatic focus adjustment motor AFU that drives the imaging lens L based on the output of the automatic focus adjustment circuit AFC. This is a motor for automatic focus adjustment. The RTC operates the trigger switch SWT in response to the operation signal of the trigger switch SWT and a signal indicating completion of focus adjustment of the imaging lens L output from the automatic focus adjustment circuit AFC, and
As shown in the figure, the recorder trigger circuit outputs a recorder trigger signal, that is, a recording start signal under the condition that the focus adjustment of the imaging lens L is completed, and the inverter IV is connected to the trigger switch SWT, and the inverter is connected to the trigger switch SWT. IV
A reset-priority type R-S flip-flop configured to receive an output from the automatic focus adjustment circuit AFC at its reset input R, and receive a signal indicating completion of focus adjustment of the imaging lens L from the automatic focus adjustment circuit AFC at its set input S. FF, and here, the Q output of the flip-flop FF is applied as a recorder trigger signal to a signal recording device system control circuit RCC having a well-known configuration on the recorder VTR side through a trigger signal output line TL and a cable CC. be done. Incidentally, in this embodiment, the trigger switch SWT is a normally open type switch that is turned on by operating the trigger button TB, and is connected to the power supply line PL as shown in the figure.・The signal of the trigger switch SWT given to the trigger circuit RTC is at low level when the trigger button TB is not operated, and the trigger switch SWT is turned on depending on the operation of the trigger button TB. If it is done, it will be at a high level. Furthermore, various types of automatic focus adjustment circuit AFC can be applied, but preferably,
It is preferable that the camera be configured to output a high level signal as a motor stop signal in order to stop the motor AFM when the imaging lens L has been adjusted to the in-focus position on the object. The high level signal is applied to the recorder trigger circuit RTC as a signal indicating completion of focus adjustment of the imaging lens L.
Specifically, as an example of the automatic focus adjustment circuit AFC, a configuration such as that shown in Japanese Patent Application No. 54-22906 filed by the applicant can be adopted, and in this case, , a high level signal is output to the motor control circuit to stop the automatic focusing motor when the imaging lens L reaches the in-focus position with respect to the object, indicating completion of focusing of the imaging lens L. This is done so that it is applied as a signal to the recorder trigger circuit RTC. Also, here, the high level signal from the Q output of the flip-flop FF serves as a trigger signal for the recorder VTR.

Furthermore, in the camera CA, GL is the ground connection line. In addition, in the recorder VTR, the PC has a power supply circuit including a power supply EE and a power switch SWP,
SWR indicates a recording switch operated by recording button RB. Incidentally, the signal recording device system control circuit RCC is
Recording after turning on the power switch SWP
In response to turning on the switch SWR, the signal recording device system
The RS is used to perform all operations necessary for recording other than tape running, such as tape loading, operation of the recording head cylinder drive motor and capstan drive motor, and operation of various circuits. and then the camera
In response to a trigger signal from the CA side, the signal recording device RS performs a tape running operation for recording, that is,
Specifically, it is configured to perform tape running operations such as pressing the pinch roller against the capstan and connecting the clutch of the tape take-up reel. Since the configuration of the signal recording device system control circuit RCC is already well known, a detailed explanation of the configuration will be omitted here.

Now, in the case of a video recording system consisting of a combination of a video camera CA and a video tape recorder VTR configured as described above, the camera CA and recorder VTR are connected by a cable.
When connected via CC, at this time, the power line PL and ground connection line GL on the camera CA side are connected to the power source EE and power switch SWP on the recorder VTR side.
In addition, the video signal output line VL and trigger signal output line TL on the camera CA side are connected to the power supply circuit PC including
are connected to the signal recording device system RS and signal recording device system control circuit RCC on the recorder VTR side, respectively, and the cable CC
are connected via each corresponding connection line within. In this state, if you operate the power button PB on the recorder VTR side and turn on the power switch SWP, the power supply installed on the recorder VTR side will turn on.
Each circuit on the camera CA side from EE, HC, TCC, VPC,
Power is supplied to AEC, AFC, RTC, etc., and the camera CA becomes operational, and on the other hand, the recorder
On the VTR side, when the recording switch SWR is turned on by operating the recording button RB, the signal recording device system control circuit RCC is activated, and the signal recording device system RS is set to the above-mentioned operating state, so that the recorder VTR is activated. The recording standby state described above is now set. With such settings,
The trigger can be triggered by aiming the camera CA at the intended object and operating the trigger button TB.
When the switch SWT is turned on, the signal of the trigger switch SWT becomes high, and the recorder trigger circuit RTC resets the flip-flop FF by changing the output of the inverter IV from high to low. Therefore, at this point, the focusing of the imaging lens L on the intended object by the automatic focusing device AFU has been completed, and the flip-flop FF from the automatic focusing circuit AFC is released.
If the set input S of When the set input S to a flip-flop FF goes high, at that point the flip-flop FF is set and its Q output changes from low to high. At this time, the high level signal from the Q output of the flip-flop FF is sent to the recorder as a recorder trigger signal through the trigger signal output line TL and cable CC.
The control circuit RCC is attached to the signal recording device system control circuit RCC on the VTR side.
Based on the trigger signal, that is, the recording start signal, it acts on the signal recording system RS to start running the tape as described above, and at this point, the video processing circuit on the camera CA side
The video signal output from VPC is used as a recorder.
The VTR will start recording on tape and start recording.

In the camera configuration shown in FIG. 2, a recording start signal is output from the camera CA side to the recorder VTR side as described above.

In the configuration shown in Figure 2, the automatic focus adjustment circuit AFC is directly connected to the power supply line PL.
Therefore, connect the camera CA to the recorder VTR,
In addition, if you keep operating the recording button RB on the recorder VTR side, there may be some concerns that it may be inconvenient because the automatic focus adjustment circuit AFC is always in operation along with other camera circuits. However, this is shown in Figure 2.
This problem can be solved by changing the connecting blocks indicated by broken lines as shown in FIGS. 3a to 3d. That is, first, the example shown in FIG. 3a is an automatic focus adjustment circuit.
Connect the AFC power supply line to the above trigger switch SWT.
By connecting to the power line PL via
Automatic focus adjustment device AFU trigger switch SWT
It is designed so that it can be activated depending on the input of the Next, the example shown in Fig. 3b shows the first and second trigger switches for the camera CA, which are configured to be turned on sequentially by operating the trigger button TB.
trigger switches SWT ₁ and SWT ₂ are provided,
The automatic focus adjustment device AFU is activated by turning on the first trigger switch SWT ₁ , while the operation signal of the second trigger switch SWT ₂ is given to the recorder trigger circuit RTC. This is what I did.

Next, the example shown in FIG. 3c is a modification of the example shown in FIG.
Other camera circuits TCC except heater circuit HC,
It is designed to be activated by turning on the first trigger switch SWT ₁ , together with VPC, AEC, etc., and the example shown in FIG. 3d is the above-mentioned
Other camera circuits TCC except heater circuit HC,
VPC, AEC, etc. using the first trigger switch above.
The automatic focus adjustment device AFU is configured to be activated when the second trigger switch SWT ₂ is activated, while the automatic focusing device AFU is activated when the second trigger switch SWT ₂ is activated. Incidentally, here, for example, the third
In the examples shown in Figures a and b, even if the camera CA is connected to the recorder VTR and the power switch SWP is turned on by operating the power button PB, the automatic focus adjustment device AFU on the camera CA side For example, in the example shown in Fig. 3c and d, the power loss of the camera circuits TCC, VPC and
Even the power loss due to AEC etc. will be significantly reduced.

Now, the operation of the system explained above corresponds to the operation related to the first mode of the present invention, and is configured such that the automatic focus adjustment device AFU continues to operate at all times while the camera CA is in operation, that is, during recording. However, in some cases, in order to be able to manually adjust the focus of the imaging lens L, the automatic focus adjustment device AFU may be added at the will of the camera user.
It may be more convenient to be able to activate the system as needed. An example of an improvement according to the present invention for such a change will be described with reference to FIG. 4.

In FIGS. 4a and 4b, CSW ₁ is a first changeover switch for switching the automatic focus adjustment circuit AFC between a first mode in which it can operate and a second mode in which it cannot operate; Circuit AFU and terminal C
The terminal A is connected to the terminal C, and the terminal M is open. Therefore, when the switch CSW ₁ is connected to the terminal A, the automatic focusing circuit AFC becomes operable as described above, but when the switch CSW ₁ is connected to the terminal M, it becomes inoperable. Therefore, the mode becomes manual focus adjustment mode. Note that the switch CSW ₁ is configured so that it can be manually operated from outside the camera CA. on the other hand,
CSW ₂ is linked to the first changeover switch CSW ₁ , and when switch CSW ₁ is connected to terminal A, it is connected to terminal A, and when switch CSW ₁ is connected to terminal M, it is connected to terminal A. is a second changeover switch similarly configured to be connected to its terminal M; in the example of FIG. 4a, said switch CSW ₂
is provided between the output stage of the automatic focus adjustment circuit AFC and the input stage of the recorder trigger circuit RTC, and its terminal A is connected to the automatic focus adjustment circuit AFC.
to the focus adjustment completion signal output terminal of , and the terminal M
is connected to the above terminal b, while FIG.
In the example above, the switch CSW ₂ is provided on the output stage side of the recorder trigger circuit RTC, and its terminal A is connected to the recorder trigger circuit RTC.
The output terminal of the RTC and its terminal M are also connected to the terminal b.

According to the above two improvements according to the present invention, when recording is performed using the automatic focus adjustment device AFU, the switches CSW ₁ and CSW ₂ are connected to their terminals A, respectively, so that the above-mentioned As in the case of the embodiment, the focusing of the imaging lens L is completed, and the trigger switch SWT (examples in FIGS. 2 and 3 a) or SWT ₂ (examples in FIGS. 3 b, c, and d) is activated. ) is operated on the recorder VTR.
The actual recording operation can now be started, but on the other hand, the automatic focus adjustment device
When recording is performed without using AFU, switches CSW ₁ and CSW ₂ are connected to their respective terminals M.
Trigger switch connected to SWT
The recording operation by the recorder VTR is started only under the condition that SWT 2 (examples shown in FIGS. 2 and 3 a) or SWT ₂ (examples shown in FIGS. 3 b, c, and d) is operated. The difference between the examples shown in Fig. 4 a and b in this case is that in the case of the example shown in Fig. 4 a, the recording start signal is generated from the recorder trigger circuit RTC by operating the trigger switch SWT or SWT ₂ . In contrast, in the case of the example shown in Figure 4b, the trigger switch
The only point is that the signal obtained by operating SWT or SWT ₂ is directly applied to the output line TL as a recording start signal.

By the way, in the embodiment described above, the camera CA is equipped with an image pickup tube IT as an imaging means, but as is generally known, in the case of an image pickup tube, it is operated at its predetermined value from the start of power supply. Since it takes a relatively long time (for example, about 10 seconds) to reach a steady state, that is, a state in which the device is sufficiently warmed up and a proper image scanning signal can be output, it is necessary to immediately Even if recording is started, proper recording will not actually begin until some time later, and there is a risk of inconveniences such as the image of the first part of the scene in particular being extremely deteriorated. Therefore, finally, a modification of the above embodiment to deal with such concerns will be described with reference to FIG. 5.

In FIG. 5, TD indicates a detection circuit for detecting whether or not the image pickup tube IT has reached a predetermined steady state, and here, TD indicates whether or not the image pickup tube IT has been sufficiently warmed up. The structure is such that it can be detected. That is, TH is a thermistor as a temperature-sensitive element, and the resistance value is changed according to the warm-up condition of the image pickup tube IT.
At least near the IT, preferably the heater circuit
It is located near the HC. _R3 is a voltage dividing resistor that constitutes a voltage dividing circuit together with the thermistor TH, and the series circuit of the resistor _R3 and thermistor TH is connected to the power supply line PL, and its voltage dividing point is the inverter of the comparator COM. connected to the input terminal. R ₁ and R ₂ are voltage dividing resistors that constitute a voltage dividing circuit, and their series circuit is connected to the power supply line PL, and the voltage dividing point is connected to the comparator.
Connected to the non-inverting input terminal of COM. Here, as the temperature around the thermistor TH rises, its resistance value decreases, and therefore,
The resistance values of the resistors _R1 and _R2 are determined by the resistance values of the resistor _R3 and thermistor TH when the potential at the voltage dividing point is warmed up to the extent that the image pickup tube IT can output an appropriate image scanning signal. It is selected to have a potential that approximately corresponds to the potential at the voltage dividing point, and this potential serves as a reference level for detecting whether the image pickup tube IT has reached a steady state. Furthermore, with the above configuration, the comparator COM outputs a signal as the output of the detection circuit TD, which remains at low level until the image pickup tube IT reaches a steady state, and becomes high level when the steady state is reached. will be output.

On the other hand, for such a detection circuit TD, the recorder trigger circuit RTC receives the Q output of the flip-flop FF and the output of the detection circuit TD, so that both output signals become high. An AND gate AG is provided which is configured to output a high level signal at the same time, and the high level signal from the AND gate AG is outputted to the output line TL as a recording start signal. Ru.

Thus, according to the modification shown in FIG. 5, the output of the recording start signal to the recorder VTR is prohibited until the detection circuit TD detects that the image pickup tube IT has reached a steady state. This is the reason why.

Note that the configuration shown in FIG. 5 shows a case in which it is combined with the embodiment shown in FIG. 4a, but it may of course be used in combination with the embodiment shown in FIG. It is. That is, in the case of Fig. 4b, the fifth
AND in the recorder trigger circuit RTC shown in the figure.
Switch the gate AG to the second selector switch in Figure 4b.
Place after CSW ₂ and flip-flop FF
Instead of connecting the Q output of the switch CSW 2, it is sufficient to connect the switch CSW ₂ to its two inputs.

Incidentally, when the focus adjustment of the imaging lens L can be performed manually as necessary according to the embodiment shown in FIGS. 4a and 4b, for example, the above-mentioned switch
In connection with switching CSW ₁ and CSW ₂ from terminal A to terminal M, the connection between the focus adjustment motor AFM and the focus adjustment mechanism of the imaging lens L is severed, and the imaging lens L is moved with very light manual force. It is preferable to configure the lens so that the focus can be adjusted.
Of course, in addition to this, a friction clutch may be inserted into the power transmission mechanism connected to the focusing motor AFM.

In addition, in connection with the modification shown in FIG.
Other methods for detecting whether the IT has reached its steady state include, for example, the level of the output of the image pickup tube IT or the video processing circuit VPC.
Various methods may be employed, such as a method of detecting based on the level of the output of Of course, this is not the case.

As described in detail above, according to the video system of the present invention, when equipped with an automatic focus adjustment device for a photographic lens whose operation or inactivation can be arbitrarily selected, the operation of the automatic focus adjustment device, The recorder trigger is now controlled in a manner corresponding to each inactivation selection, and the inconvenience that the image at the beginning of the scene is likely to deteriorate in any case is avoided, and the trigger is always set at the beginning of the scene. This makes it possible to perform recording in good condition from the start, and is extremely useful in this type of video system.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a video recording system comprising a combination of a video camera and a cassette-type video tape recorder according to the present invention, and FIG. 2 is a schematic diagram showing an example of the video recording system shown in FIG.・In the system configuration, a block circuit diagram showing the configuration of the main electric circuit system related to the present invention with the camera and recorder connected. Partial circuit diagrams showing four modifications of the trigger section,
FIG. 4 is a partial circuit diagram showing two improved examples of the camera circuit shown in FIG. 2 according to the present invention, particularly the main circuits related to the improvement, and FIG. 5 is a modification of the camera circuit shown in FIG. 2. FIG. 6 is a partial circuit diagram showing a circuit of an example, particularly a main part related to a change. CA...Camera, L...Imaging lens, AFU...Automatic focus adjustment device, AFC...Automatic focus adjustment circuit, AFM...
Auto focus adjustment motor, TB...trigger button, SWT; SWT ₁ , SWT ₂ ...trigger switch,
RTC...Recorder trigger circuit, CSW ₁ ...Switch switch, CSW ₂ ...Auxiliary means (switch switch), TD
…detection means, AG…inhibition gate (and gate), VTR…video recorder, PB…power button, SWP…power switch, RB…recording button, SWR…recording switch,
RS...Signal recording device system, RCC...Signal recording device system control circuit.

Claims (1)

[Claims] 1 A video system that includes a video camera that converts a subject image into an electrical signal and outputs it, and a video recorder that records the electrical signal output from the video camera on a recording medium, which an automatic focus adjustment device that automatically focuses the video recorder; a first switch that sets the video recorder to a recording standby state in which the recording head and the recording medium move relative to each other; and a trigger member that operates the video recorder; and a recorder trigger circuit that receives a signal indicating completion of focus adjustment of the photographing lens outputted from the automatic focus adjustment device and an operation signal of the second switch, The trigger circuit is configured such that in a first mode, when the video recorder is set to the recording standby state by the first switch, the second switch is operated and the focus adjustment of the photographing lens is performed. The recording by the video recorder is started on the condition that the recording is completed, and in the second mode, when the video recorder is set to the recording standby state by the first switch, the focus adjustment state of the photographing lens is Regardless of the above, the video system is characterized in that the video recorder starts recording in response to the operation of the second switch.